At the present technical stage, all friers produced and xarketed for home use are equipped with vertically-moving baskets only. These types of baskets serve food introduction, extraction and/or draining purposes well, but cannot move during cooking.
However, vertically-moving baskets are inconvenient for a number of reasons.
A first important reason is the high quantity of oil needed for proper cooking, which also means (a) high operating costs due to high power consumption; (b) changing of great quantities of oil due to its exhaustion or to adapt it to the type of food to be cooked.
A second equally important reason is of practical nature, and consists in having to repeatedly move by hand the basket to separate the various food pieces during cooking, which may be rather difficult during the intermediate cooking phases. Furthermore, food cannot be uniformly cooked; the temperature of the oil bath cannot be easily raised; water vapor cannot be freely dispersed; proper cleaning of the oil tray is difficult, even in those cases where the basket can be removed.